Biomedical subjects

Jia-ping Peng

Publications and source records attributed to Jia-ping Peng.

8 recordsLinked to original sources

PubMed2006

[Establishment of DNA oxidative damage model in colorectal crypt cells by hydrogen peroxide].

OBJECTIVE: To induce DNA oxidative damage in colorectal crypt cells by hydrogen peroxide in vitro. METHODS: Hydrogen peroxide was diluted into 100, 50, 10, 5 and 1 micromol/L with RPMI 1640. Colorectal crypt cells were treated with peroxide for 10 min, 30 min, 1 h, 1.5 h, 12 h and 24 h respectively. The survival of colorectal crypt cell was measured by MTT method, and the DNA oxidative damage special product, 8-OhdG was detected with immunohistochemical staining. Liner regression was used to measure the time trend of survival rate with SPSS 10.0 software. RESULT: Survival rate of colorectal crypt cell was 60% and 80% after 10 min of hydrogen peroxide treatment. The longer treatment of hydrogen peroxide, the lower survival rate; the survival rate was reduced to 30% in 24 h. After 10 or 30 min treatment of 100 or 50 micromol/L hydrogen peroxide, the survival rates of colorectal crypt cells were reduced by 20% compared with those of 10, 5 and 1 micromol/L hydrogen peroxide. However, while cells were treated with different concentrations of hydrogen peroxide for 1.0 h or above, there were no differences in cell survival rates. The time trend test results demonstrated that the survival rates of colorectal crypt cells treated with 10, 5 and 1 micromol/L hydrogen peroxide were significantly decreased with the time length of treatment. Colorectal crypt cells treated with different concentrations of hydrogen peroxide for 15 minutes were positively stained brown in cytoplasm and nuclear by immunohistochemistry with 8-OhdG monoclonal antibody. CONCLUSION: Hydrogen peroxide could induce DNA oxidative damage in colorectal crypt cells. And treated with 1 - 10 micromol/L hydrogen peroxide for 10 - 30 min, DNA oxidative damage is apt to be induced in colorectal crypt cell.

Carbazoles↗

PubMed2005

[Clinical analysis of 39 cases of heterotopic gastric mucosa in the upper esophagus].

OBJECTIVE: To determine accurately the incidence of heterotopic gastric mucosa in the upper esophagus (HGMUE) in China, and to study the macroscopic and microscopic aspects of the lesions and to evaluate the clinical importance of HGMUE. METHODS: A prospective study was made among a total of 15,228 consecutive patients, 8,573 male and 6,655 female, aged 54 (8-95), undergoing gastroscopy. Disease histories of all patients were carefully inquired, especially those regarding possible complaints including discomfort of throat and swallowing pain and so on. Special care was taken in the upper esophageal sphincter area to make sure whether the area was adequately inspected. Biopsy specimens from aberrant mucosa were obtained and the sections were stained with haematoxylin and eosin, and Giemsa stain for Helicobacter pylori. RESULTS: HGMUE was found in 39 patients (0.26%) with an average age of 50. Five patients with H. pylori infection in heterotopic gastric mucosa also presented the infection in the stomach. The gastric mucosa was gastric body type in 8 patients, transitional type in 11 patients, and antral pattern in 7 patients. Intestinal metaplasia was found in 5 patients, and mild atypical hyperplasia in 2 patients. An impressive finding was coexistent erosive gastritis in 14 patients (35.9%), Barrett's esophagus in one patient (2.6%), peptic ulcer in 8 patients (20.5%), and a patient had the complication of constriction in the upper esophagus. CONCLUSION: HGMUE is not rare in China. The presence of inlet patches is possibly correlated with specific symptoms. There are some severe complications in HGMUE, especially esophageal constriction. Close surveillance should be taken for rare cases with metaplasia or dysplasia in HGMUE.

Adolescent↗

PubMed2005

Prognostic significance of bcl-2 and p53 expression in colorectal carcinoma.

OBJECTIVE: This study was designed to detect the expression of bcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. METHODS: Immunohistochemistry method was used to detect the expression of bcl-2 and p53 proteins in 93 cases of colorectal carcinoma. The stain results were obtained by analyzing the clinic-pathological characteristics of patients. RESULTS: Fifty-seven percent (53/93) of the colorectal carcinomas were bcl-2 protein positive. The positive rate of bcl-2 protein in lymph node involvement cases was lower (15/37) than the cases without node involvement (38/58, P<0.01). The positive rate of p53 protein was 43% (40/93) in colon-rectum carcinomas. No significant correlation was observed between p53 protein expression and clinic-pathological manifestations (P>0.05) but the survival was significantly worse (P=0.0001) in the p53 protein positive cases. Neither bcl-2 nor p53 alone was correlated with stage of the disease. When combined bcl-2/p53 status was analyzed, a group with bcl-2(+) and p53(-) had the best prognosis. This group was significantly associated with earlier Dukes' stages (P=0.1763). In multivariate Cox regression analysis, lymph node involvement and p53 protein expression were two independent factors correlated with survival time. CONCLUSION: The expression of bcl-2 and p53 represent biological characteristics of colorectal carcinomas. Assessment of both bcl-2 and p53 status may be valuable in predicting the prognosis of patients.

Biomarkers, Tumor↗

PubMed2005

[Effects of microencapsulated CHO cells modified with maspin gene on the motility and adhesiveness of breast carcinoma cells Bcap37].

OBJECTIVE: To investigate the effects of microencapsulated Chinese hamster ovary (CHO) cells modified with maspin gene on the motility and adhesiveness of breast carcinoma cells Bcap37 and to explore the possibility and feasibility of its clinical application in treatment of malignant tumors. METHODS: After the Bcap37 cells were co-cultured with the microencapsulated CHO cells modified with maspin gene, their motility and adhesion to vascular endothelial cells (ECV304), changes in CD44v6 and E-cadherin expression were examined. RESULTS: After the treatment, the motility of Bcap37 cells, their adhesion to vascular endothelial cells ECV304 and the CD44v6 expression were significantly reduced. The adhesiveness of Bcap37 cells and their E-cadherin expression were significantly enhanced. CONCLUSION: The microencapsulated CHO cells modified with maspin gene decrease motility and adhesiveness of breast carcinoma cells Bcap37, which help explain the anti-metastatic effects of maspin.

Animals↗

PubMed2005

[Development of ZM-1 tissue microarrayer].

ZM-1 tissue microarrayer designed by our group is manufactured in stainless steel and brass. It features an easier and faster preparation for tissue microarrays. By means of it, a group of biopsy needles are used to punch the donor tissue specimens respectively, and all the needles with the punched specimen cylinders are arranged into the array-board, where small holes have been digged to fit the needles. All the specimen cylinders arraying and the tissue microarray block's shaping are finished simultaneously. ZM-1 tissue microarrayer with a lower cost of manufacture, is capable of preparing the tissue microarrays conveniently, efficiently and quality-controllably.

Equipment Design↗

PubMed2004

[A study of the abnormalities of human epiderm in keloids and hypertrophic scars].

OBJECTIVE: To investigate the abnormalities of human epiderm in keloids and hypertrophic scars. METHODS: Biopsies from ten untreated keloids (duration of disease 3 - 30 years) and ten hypertrophic scars (duration of disease 6 - 10 months) and five normal adult skin specimens. Total RNA was isolated from normal adult skin. A cDNA fragment (base 5941 - 6481 bp) of the full-length human Tenascin-C cDNA was synthesized by polymerase chain reaction and subcloned in pGEM-T-easy. Dioxigen-labeled anti-sense and sense probes were synthesized by using a Sp6/T7 in vitro RNA synthesis kit in the present of Dig-UTP. In situ hybridization was performed on 4% paraformaldehyde-fixed and wax-embedded sections of keloids and hypertrophic scars. NBT-NCIP was used in color detection. Immunohistochemical procedure. The sections were incubated with antibodies (anti-Tenascin-C, anti-CK-16 and anti-Ki-67). Ultrasensitive Streptavidin Peroxidase staining was performed following established procedures. RESULTS: The study show that the proliferation of epidermal keratinocytes in keloids and hypertrophic scars is very clear. The expressions of Tenascin-C mRNA in keloids epidermal keratinocytes markedly increased in contrast with epidermal keratinocytes of hypertrophic scars and adult skin. The CK-16 and Ki-67 stainings significantly enhanced in the epidermal keratinocytes of keloids and hypertrophic scars. CONCLUSIONS: The different expressions of Tenascin-C, CK-16 and Ki-67 among normal adult skin, keloids and hypertrophic scars show the abnormalities of epidermal keratinocytes proliferation and differentiation in keloids and hypertrophic scars.

Cicatrix, Hypertrophic↗

PubMed2004

Study on interleukin-18 gene transfer into human breast cancer cells to prevent tumorigenicity.

To study the effect of interleukin-18 gene transfection on the tumorigenesis of breast cancer cell line Bacp37, human breast cancer cell line Bcap37 were transfected with Lipofectamine and selected by G418. The biological expression of rhIL-18 was tested by RT-PCR and ELISA method; nude mice were injected with Bcap37 cell with or without the hIL-18 gene. The hIL-18 cDNA was successfully integrated into Bcap37 cell; 126.3+/-4.5 pg hIL-18 secreted by one million transduced cells in 24 hours. Nude mice injected with IL-18 gene engineered Bcap37 cell had no tumor growth. These findings indicated that human breast cancer cells were successfully modified by the gene of IL-18 cytokine; the IL-18 gene engineered Bcap37 cells secreted hIL-18 and lost their tumorigenicity. The Bcap37 cells transduced with IL-18 gene may be used as breast cancer vaccine.

Animals↗

PubMed2003

[The study of 5-Aza-2'-deoxycytidine on transcription regulation of p16/CDKN2 gene demethylation in RKO human colorectal cell line].

OBJECTIVE: To explore the transcription regulation of DNA 5'CpG island demethylation on p16/CDKN2 tumor suppressor gene and effects of growth on RKO human colorectal cancer cell line. METHODS: RKO cell line was exposed to the specific demethylating agent, 5-Aza-2'-deoxycytidine, for seventy-two hours to detect whether the silencing of p16/CDKN2 cell cycle regulatory gene could be reversed. Methylation-specific PCR (MSP), T-A cloning and sequence analysis were evaluated for methylation status. Growth speed, expression of DNA methyltransferase mRNA, p16/CDKN2 mRNA and protein were determined by MTT assay, reverse transcription polymerase chain reaction (RT-PCR), Real-time PCR, immunohistochemistry and western blot. RESULTS: (1) All cytosines in CpG dinucleotides in untreated RKO cells with 5-Aza-2'-deoxycytidine remain as C, while all cytosines in treated RKO cells have been converted to thymidine. (2) RKO cell line after treatment with three different concentration 5-Aza-2'-deoxycytidine grew slowly and double time increased to 1.49, 1.64, 1.87-times respectively. (3) The expression of RKO cell p16/CDNK2 gene mRNA treated with 5-Aza-2'-deoxycytidine increased to 4.89, 16.91, 19.97-times respectively, but the expression of DNA methyltransferase mRNA was inhibited. (4) Immunohistochemistry and western blot indicated that 5-Aza-2'-deoxycytidine could increase the p16/CDKN2 gene protein expression. CONCLUSION: DNA promoter hypermethylation is associated with p16/CDKN2 gene silence in RKO human colorectal cancer cell line. 5-Aza-2'-deoxycytidine may effectively cause demethylation and inhibit the growth of tumor cell by reactivating the gene transcription silenced by aberrant hypermethylation.

Antimetabolites, Antineoplastic↗